The present invention relates generally to an imaging system and an identity authentication system, and more particularly to an imaging system for imaging the state of the fundus of the eye in a divided fashion and an identity authentication system incorporating the same.
So far, there has been known an identity authentication system wherein a fundus camera is used for imaging the state (retinal blood vessel pattern) of the fundus of the eye for the purpose of identity authentication.
FIG. 15 is illustrative of the construction of an optical system used with such an imaging system. In that optical system, a relay optical system 100 is located in front of an eyeball E the image of which is to be picked up. This relay optical system 100 projects an image of a pupil P of the eyeball E onto an entrance pupil 102 of an imaging lens 101. An image of the retina R projected through the crystalline lens LC of the eyeball E at a distance is projected through the relay optical system 100 as a real image in front of the imaging lens 101. In turn, this real image is projected through the imaging lens 101 so that it is formed as a fundus image on an imaging device 103. Trait data is extracted from the fundus image formed by the imaging device 103 for identity authentication or identification.
To pick up images over a wide range of the retina R through a small pupil P, the prior art must use a large lens system as the relay optical system 100. To reduce pupil aberrations, it is also required to use an aspheric surface or a cemented lens in the relay optical system 100.
With an identity authentication system, the head of a person must be positioned at a constant spacing with respect to a fundus camera and in a predetermined direction.